From 88c9cfade96f2b7e1fd7ab8cc134c189c94bcff6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=89der=20F=2E=20Zulian?= <zulian@eit.uni-kl.de>
Date: Thu, 7 Jul 2016 16:57:54 +0200
Subject: [PATCH] Using mmap to allocate virtual memory instead of a std:map.

---
 DRAMSys/simulator/src/simulation/Dram.h | 63 +++++++++----------------
 1 file changed, 21 insertions(+), 42 deletions(-)

diff --git a/DRAMSys/simulator/src/simulation/Dram.h b/DRAMSys/simulator/src/simulation/Dram.h
index bb608c41..b6e38ca6 100644
--- a/DRAMSys/simulator/src/simulation/Dram.h
+++ b/DRAMSys/simulator/src/simulation/Dram.h
@@ -39,6 +39,8 @@
 #ifndef DRAM_H_
 #define DRAM_H_
 
+#include <sys/mman.h>
+
 #include <tlm.h>
 #include <systemc.h>
 #include <tlm_utils/peq_with_cb_and_phase.h>
@@ -88,7 +90,7 @@ struct Dram : sc_module
     std::vector<errorModel *> ememory;
 
     // Data Storage:
-    map< unsigned long int, std::vector<unsigned char> > memory;
+    unsigned char *memory;
 
     TlmRecorder *tlmRecorder;
     Controller *dramController;
@@ -97,6 +99,10 @@ struct Dram : sc_module
     {
         ZEROES.assign(bytesPerBurst, 0);
 
+        // FIXME: memory size
+        unsigned int size = 1024 * 1024 * 1024;
+        memory = (unsigned char *)mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON | MAP_NORESERVE, -1, 0);
+
         tSocket.register_nb_transport_fw(this, &Dram::nb_transport_fw);
         tSocket.register_transport_dbg(this,&Dram::transport_dbg);
 
@@ -382,8 +388,8 @@ struct Dram : sc_module
             }
             else if (ErrorStoreMode == ErrorStorageMode::Store) // Use Storage
             {
-                memory[payload.get_address()].reserve(bytesPerBurst);
-                memcpy(memory[payload.get_address()].data(), payload.get_data_ptr(), payload.get_data_length());
+                unsigned char *phyAddr = memory + payload.get_address();
+                memcpy(phyAddr, payload.get_data_ptr(), payload.get_data_length());
             }
             else // == 2 Use Storage with Error Model
             {
@@ -401,15 +407,8 @@ struct Dram : sc_module
             // Load data:
             if (ErrorStoreMode == ErrorStorageMode::Store)    //use ErrorStorageMode
             {
-                if(memory.count(payload.get_address()) == 1)
-                {
-                    memcpy(payload.get_data_ptr(), memory[payload.get_address()].data(), payload.get_data_length());
-                }
-                else
-                {
-                    SC_REPORT_WARNING ("DRAM", "Reading from an empty memory location.");
-                    memcpy(payload.get_data_ptr(), ZEROES.data(), payload.get_data_length());
-                }
+                unsigned char *phyAddr = memory + payload.get_address();
+                memcpy(payload.get_data_ptr(), phyAddr, payload.get_data_length());
             }
             else if(ErrorStoreMode == ErrorStorageMode::ErrorModel)// use ErrorStorageMode with errormodel
             {
@@ -430,8 +429,9 @@ struct Dram : sc_module
             }
             else if (ErrorStoreMode == ErrorStorageMode::Store) // Use Storage
             {
-                memory[payload.get_address()].reserve(bytesPerBurst);
-                memcpy(memory[payload.get_address()].data(), payload.get_data_ptr(), payload.get_data_length());
+
+                unsigned char *phyAddr = memory + payload.get_address();
+                memcpy(phyAddr, payload.get_data_ptr(), payload.get_data_length());
             }
             else // == 2 Use Storage with Error Model
             {
@@ -447,15 +447,8 @@ struct Dram : sc_module
             // Load data:
             if (ErrorStoreMode == ErrorStorageMode::Store)    //use ErrorStorageMode
             {
-                if(memory.count(payload.get_address()) == 1)
-                {
-                    memcpy(payload.get_data_ptr(), memory[payload.get_address()].data(), payload.get_data_length());
-                }
-                else
-                {
-                    SC_REPORT_WARNING ("DRAM", "Reading from an empty memory location.");
-                    memcpy(payload.get_data_ptr(), ZEROES.data(), payload.get_data_length());
-                }
+                unsigned char *phyAddr = memory + payload.get_address();
+                memcpy(payload.get_data_ptr(), phyAddr, payload.get_data_length());
             }
             else if(ErrorStoreMode == ErrorStorageMode::ErrorModel)// use ErrorStorageMode with errormodel
             {
@@ -566,15 +559,8 @@ struct Dram : sc_module
             {
                 if (ErrorStoreMode == ErrorStorageMode::Store) // Use Storage
                 {
-                    if (memory.count(adr) == 1)
-                    {
-                        memcpy(ptr, memory[adr].data(), len);
-                    }
-                    else
-                    {
-                        SC_REPORT_WARNING ("DRAM", "Reading from an empty memory location.");
-                        memcpy(ptr, ZEROES.data(), len);
-                    }
+                    unsigned char *phyAddr = memory + trans.get_address();
+                    memcpy(trans.get_data_ptr(), phyAddr, trans.get_data_length());
                 }
                 else
                 {
@@ -584,16 +570,9 @@ struct Dram : sc_module
             }
             else if ( cmd == tlm::TLM_WRITE_COMMAND )
             {
-                if (ErrorStoreMode == ErrorStorageMode::Store) // Use Storage
-                {
-                    memory[adr].reserve(bytesPerBurst);
-                    memcpy(memory[adr].data(), ptr, len);
-                }
-                else
-                {
-                    //ememory[bank]->store(trans);
-                    SC_REPORT_FATAL("DRAM", "Debug transport not supported with error model yet.");
-                }
+
+                    unsigned char *phyAddr = memory + trans.get_address();
+                    memcpy(phyAddr, trans.get_data_ptr(), trans.get_data_length());
             }
             return len;
         }